Optical networks transmit information encoded into light signals among various nodes of a telecommunications network. These networks can be configured to operates as local-area network (LAN) or wide-area network (WAN). Because optical networks are capable of achieving extremely high bandwidth, such networks are well suited for use in Internet and telecommunication applications.
However, optical networks are susceptible to the same types of problems that affect electronic networks. For example, optical connections between the nodes may fail or power outages may degrade performance or limit operation. To address these problems, optical networks have been developed with various protections mechanisms that attempt to re-route optical transmissions in the event of a connection failure or power outage.
The optical switch is a key component in a protection system. There are two types of optical switches, namely, a non-latching type and a latching type. Both types operate in a known way when power is removed. For example, the non-latching type optical switch will switch to a bypass mode or “power off state” when power is removed. The latching type optical switch will latch and maintain the light path used when power is lost. These are considered “physical” protection mechanisms used in conventional network protection solutions.
Unfortunately, when upgrade and maintenance of network occurs or when power is off, these physical protection mechanisms can't adjust the light path according to new requirements. This is because the optical switch changes the light path to the protection mode automatically. This results in networks that lack flexibility and performance.
Therefore, it is desirable to have a mechanism for use in optical networks that provides enhanced flexibility in routing signals and that provides greater flexibility than physical protection modes to protect optical networks in the event of network failures or power outages.